THE ORIGIN AND DEVELOPMENT OF BULBS IN THE 
GENUS ERYTHRONIUM!? 
FREDERICK H. BLODGETT 
(WITH PLATES VIII-X AND SEVEN FIGURES) 
Introduction 
The genus Erythronium includes some fifteen species of bulbous 
plants of the north temperate zone, one of which occurs from the 
Pyrenees, across France, southern Europe, and Asia, to Korea and 
Japan. The remaining species are North American. 
The plants are perennial through the annually renewed bulbs. 
These are developed at gradually increasing depths from the seed- 
ling to the flowering stage, after which they are formed at a nearly 
constant depth in the soil. The bulb consists of a few thick scales 
surrounding the stem apex; the aerial structures push upward 
from the base through the cavity inclosed by the inner scale. The 
first aerial structures are single leaves, two leaves and flowers 
appearing only after several years. | 
Special details of the development of one or another of the 
species have been examined by several writers; but some stages 
have been omitted in these accounts, and in others some obscurity 
exists as to the exact nature of the structures mentioned. A con- 
secutive account of the development of the plant, with special 
reference to the origin and structure of the stem apex, and its 
outgrowths, from its inception in the embryo to the final formation 
of the flower bud, is the subject of this paper; which is thus a study 
of the vegetative development of the sporophyte, consideration of 
the gametophyte being omitted. 
Erythronium americanum is taken as the basis of the study, 
since material of this species is abundant in the vicinity of B sk 
more, and especially since it shows more specialization in 1 
vegetative development than do the other forms. Comparisons 
have been made with other species, as will be noted, and the 
« Contribution from the Botanical Laboratory of the Johns Hopkins University, 
no. 14. 
Botanical Gazette, vol. 50] [349 
